This invention relates to a method and associated apparatus for detecting an abnormal medical condition of a patient's limb. More particularly, this invention pertains to a method and associated apparatus for monitoring limbs for the abnormal infusion of fluids into the limbs.
In certain kinds of thoracic surgery, e.g., open heart surgery, it is necessary to keep the arms of the patient extending alongside the patient's flanks. This arm configuration maximizes the number of surgical personnel who can stand beside the patient. At least one arm of the patient is infused with blood via an intravenous catheter. The arm and the catheter are covered with a drape sheet during the operation.
Because the patient is occasionally moved during surgery, the catheter can become displaced and can perforate the vein so that blood infiltrates the tissues of the arm rather than being fed into the cardiovascular system. Because the arm is covered, the infiltration is frequently not detected until the missing blood results in other symptoms. Infiltration can also result in a so-called compartment syndrome wherein the pressurized fluid in the muscular tissues collapses arteries feeding the arm and thereby prevents oxygenation of the tissues of the arm.
Clearly, infiltration represents a serious problem in thoracic surgery.
A different sort of problem in hospitals is phlebitis, particularly in the patients' legs. A need exists for a technique which will result in the early detection of phlebitis, before the condition becomes severe.